Trailer wheels tyres

Says 60psi on the tyre. That seems a bit high to me!!

Rick

If you look at a tyre on something like a racing bike (which has a Schroeder valve btw), they are pumped up to a minimum of 120psi, so I don't think the Schroeder valve is the deciding factor.

Good call on Hysteresis heating as this combined with friction (due to rolling surface area) are the primary causes of wear and tear on a tyre.  An under inflated tyre is arguably more of a danger that over inflation

I'd be a lot more worried about killing your hull. Trailing is bad for hulls but softer tyres are better because the boat is bounced around less. I really wouldn't pump dinghy trailer tyres to the max. 25psi should be plenty. Keelboat trailer tyres are different and need high pressure, due to the weight of the boat.

Regarding changing tyres, I think it is pretty difficult to DIY without the tools that tyre shops use to peel the tyre on and off the wheel. A good type shop will change a trailer tyre for you - I've had to get it done due to a puncture.

At 25psi with those small tyres, I'd have thought there's a fairly high risk you'll hit a bump and stretch the bead away from the rim enough to lose all the air in the tyre.

I'm sure that somewhere there must be a list of tyre pressures for axle loads for tyres, but I think 6 ply tyres go up to 75psi at maximum axle load of about 500kg.

Remember as well that those small wheels are only rated up to 60mph - anything above this they start to get seriously warm! Not that anyone ever exceeds the speed limit with a trailer of course

If you can, fit ten inch wheels with radial tyres - these allow a maximum speed of 150kph

Having experienced a "blowout" on a boat trailer on the motorway a few months back (not my trailer) I can say with reasonable authority that it is a complete non event in comparison to one on a car due to the trailer being so light. My passenger (the owner of the boat and trailer!) didn't even realise there was anything major wrong - he thought the banging was the trailer strap come loose. On getting out though, having coasted down from about 50 to 0mph, there wasn't much left of the mudguard, interesting skid marks on the side of the boat, and no sign of any tyre left (spread over about 1/4 of a mile of M4), just a completely destroyed wheel rim.